#but thats really the only place this mutation pops up and the mechanism is super interesting

[hey-hamlet]

can you share your theory on the premature aging please i am really interested

Ok so! This is gonna be kinda nerdy - jargon translations at the bottom.

One of my 'how quirks work genetically' theories is that the quirk virus made germline mutations way more common - tanking the fertility rate bc some of the mutations were incompatible with life, but a a lot of those other mutations led to weird hair, skin and eye colours along with quirks. In real life viruses don't do this directly, some but can incorporate themselves into genomes in fragile places that can, indirectly, increase mutation rates. Also in real life these mutations just give you cancer, but anyway.

Another driver of mutation is stress - like real actual 'my life is a mess' stress, but specifically in this case I'm talking about oxidative stress - this can be caused via aforementioned real actual stress, lifestyle problems, immune system responses, etc. Normal metabolism also induces oxidative stress - OFA uses a *lot* of energy - even if it isn't all from calories, it's still got to be used like ATP!

Basically, you get OFA, and a quirk? Your body is mutation central.

Now you may be thinking - hang on, didn't you just say that all those mutations give you cancer? Where is the aging coming in? And honestly fair enough. Oxidative damage is believed to play some part in aging, but not the main part and it wouldn't explain why being quirkless protects you from it.

The answer is lamins - the weird part of the cell you never think about. Lamins are proteins that form a sort of mesh that keeps your cell nuclei nice and round, allowing for easy cell division and nice neat DNA organisation. Progeria is a rare disease caused by a single nucleotide mutation in the gene coding for the processing of lamins, causing them to fold incorrectly, leading to misshapen nuclei. The symptoms of this disease can be simplified to fatal accelerated and premature aging. These lamins and the associated abnormal nuclei can also be found in, unsurprisingly, the elderly (well, in everyone, but the quantity goes up with age).

This disease is typically a germline cell mutation itself, but now we get to play with the quirk virus (and also fudge genetics a touch). If the quirk virus inserted itself near the lamin gene, the chances of mutation are boosted - now, normally those mutated cells would just get cleared away by the immune system and everyone is happy. But, factor in the massive amounts of oxidative stress OFA causes on the already fragile region of DNA and we start accumulating these mutations in the lamin genes all over the place, causing that rapid and fatal aging seen in OFA wielders that have quirks.

jargon translations: germline mutation: mutation within germ cells - egg or sperm - that can pass on to your children. oxidative stress: you know how oxygen rusts metal? wild over simplification, but something a lot like that happens inside you. antioxidants (eaten and produced by the body) are 'easier to rust' and use up all of the reactive oxygen to keep your cells safe. ATP: adenosine triphosphate - the food you eat eventually ends up as this through a long and convoluted collection of pathways, and its the way your cells can actually make use of it. nucleotide: one of the 4 letters your DNA is made up of - in its simplest form, your DNA is just two matching strands made up of a bunch of these letters which your body reads like a computer reads binary code.

sources: i'm not citing them because i do enough of that in university, but studies, my course content and also wikipedia because sometimes you just need to make sure something you though you knew was right or not. you also do not actually need to trust me because this is just a fan theory about an anime, it just needs to sound good. to my knowledge i'm correct though, but have wildly over simplified a lot